ISCHIA, Italy (AP) — The Group of Seven industrialized nations threw their support behind a new technology industry alliance aimed at detecting and blunting online propaganda, saying Friday it had a "major role" to play in combatting extremism on the internet.

G7 interior ministers meeting in Italy invited representatives from Google, Microsoft, Facebook and Twitter to a session Friday dedicated to the fight against terrorism. In a final communique, the ministers pressed the industry as a whole to do more.

"Internet companies will continue to take a proactive role and ensure decisive action in...